1. Field of the Invention
the present invention relates to an apparatus in which laser output power of a continuous-wave (CW) gas laser device is stabilized by the feedback control of discharge current with an auxiliary electrode in the gas discharge laser.
The gas discharge laser can be divided into such three parts as a resonator, a power supply and a laser (gas) medium and the fluctuation of laser output power is caused by the changes of the discharge condition, the gas condition and the resonator condition.
2. Description of the Related Art
In order to stabilize laser output power fluctuation, methods in which laser output power is stabilized by controlling the current of main power supply or, in the case of single mode laser, by controlling the length of resonator have been used so far. In order to stabilize the laser output power fluctuation, the current of the main discharge power source is controlled or, in the case of a single mode laser, the length of the resonator is controlled.